Fluoride topical applications

As there is no remodelling for enamel and dentine mineral, the incorporation process of fluoride appears in these cases rather different. Two processes have been considered the fluoride uptake during tooth formation and the uptake resulting from saliva and/or topical applications. The fluoridation process of... 

Several experiments have shown the bactericidal effect of fluoride ions at high concentrations [180,181]. This effect generally occurs at concentrations well above those generally observed in saliva however, the use of fluoridated toothpaste or dental topical applications of fluoride may temporarily elevate the fluoride concentration in the oral cavity to bactericidal levels. It has been demonstrated that fluoride affects the metabolism of oral bacteria and reduces its acid tolerance. It is most effective at acidic pH values and, for example, fluoride levels as low as 0.1 mM can cause the complete arrest of glycolysis by Steptococcus mutans. It has been suggested that modifying the biological fluids related to the presence... 

Fluoride in drinking water appears to be most effective in preventing dental caries if consumed before the eruption of the permanent teeth. The optimum concentration in drinking water supplies is 0.5-1 ppm. Topical application is most effective if done just as the teeth erupt. There is little further benefit to giving fluoride after the permanent teeth are fully formed. Excess fluoride in drinking water leads to mottling of the enamel proportionate to the concentration above 1 ppm. 

Dental plaque also tends to concentrate fluoride. This could increase possible antienzymatic activity. Some caries protection from this may be expected. Additionally, studies have suggested that topical application of fluoride may also reduce smooth surface plaque, with a resulting beneficial effect on the periodontal tissues. 

The use of dietary fluoride or topical applications of fluoride depends partly on the age of the child. Dietary supplements of fluoride are best for very young children, whereas topical fluoride applications are preferred for older children with permanent teeth. Younger children who are highly susceptible to caries may benefit from both measures. 

Microbial plaque is the primary cause of both deutal caries and periodontal disease [134,135]. In principle, most plaque can be ranoved using appropriate oral hygiene devices, such as toothbrushes aud dental floss, but in practice many patients lack both the skill and the motivation to maintain a reliable plaque-free state [136]. For this reason, professional dental prophylaxis has an important part to play in helping maintain sound oral health in individuals. The primary function of such prophylaxis is ranoval of plaque, stain and calculus [137] and elimination of the factors that cause plaque to build up and be retained [138]. This may be augmented by the topical application of fluoride in an appropriate form. 

Tire level of fluoride in fasting saliva which normally ranges from O.S to 2.5 jumol dm depends on the sampling time relative to the individual and the quantities of fluoride consumed [190,308,310,355,356]. These trace quantities could be of importance in preventive densitry since dental surfaces are virtually subjected to continuous topical application of fluoride from the salivary glands. 

The particular properties of HF forced the scientific community to understand its mechanism and its lesions kinetics (see Sect. 4.1.2.1). The idea was to find a way to improve the water washing. But the first improvement was to add, after initial decontamination with water, a secondary treatment such as to apply calcium gluconate as an ointment or by intravenous or subcutaneous injection. Topical applications are easier to perform but require repeated ointment based on patient s pain. Hydrofluoric acid bums are very painful. The pain depends on the concentration. If the concentration is higher than 50 %, the sensation of pain is immediate. If the concentration is less than 50 %, the pain and the lesions can be delayed. Calcium gluconate limits the evolution of the bum by binding fluoride ions but has only a light effect on H+ ions. 

With this model of human skin explant, after the validation of the experimental bum, the challenge was to compare various methods for washing HF bums. We selected two of them water washing followed by application of a 2.5 % calcium gluconate (CaG) cutaneous gel with topical application versus HEXAFLUORINE solution as a specific washing solution, which, due to its anti-acid and fluoride ion-chelating properties, matches the two dangers of HF corrosion and toxicity. 

Once teeth have erupted the effectiveness of systemically derived fluoride is questionable and it is then necessary to ensure that the fluoride comes in contact with the external surface of the tooth. Various methods of topical application have been tried but they provide relatively poor caries protection and require a large expenditure in terms of organization and time. Fluoride-containing toothpastes are now widely available and if used regularly have an appreciable effect (Chapter 36). 

It is likely that most small children swallow some of the paste and this possibility should be considered when fluoride tablets are prescribed due to the dangers of an excessive dose (page 147). Topical application may also be carried out by dentists and dental auxiliaries using acidic phosphate-fluoride gels applied to the tooth surface for several minutes. A low pH value is needed to drive the reaction... 

Moreover, the best analytical procedures available have failed to reveal an increase in the fluorine content of topically treated teeth, although most of the studies of topical applications of fluoride to tooth surfaces have demonstrated caries-preventive effects. The most likely explanation seems to be that fluorine influences the physical and biochemical properties of teeth and particularly of enamel surfaces in vivo perhaps by the surface absorption of minute amounts of fluorine by the OH-apatite of the enamel with the production of a protective layer of acid-resisting fluorapatite. Studies with radioactive fluorine have shown that enamel, dentine, bone, and OH-apatite absorb fluorine according to the Freundlich adsorption isotherm.That physicochemical changes do occur which confer acid-... 

D.T. Zero, R.F. Raubertas, J. Fu, A.M. Pedersen, A.L. Hayes, J.D.B. Featherstone, Fluoride concentrations in plaque, whole saliva, and ductal saliva after application of home-use topical fluorides, J. Dent. Res. 71 (1992) 1768-1775. 

D.W. Johnston, D.W. Lewis, Three-year randomized trial of professionally applied topical fluoride gel comparing annual and biannual application with/without prior prophylaxis. Caries Res. 29 (1995) 331-336. 

B. Ogard, L. Seppa, G. Rolla, Professional topical fluoride applications—Clinical efficacy and mechanism of action, Adv. Dent. Res. 8 (1994) 190-201. 

Advances in Fluorine Science is a new book series presenting critical multidisciplinary overviews on areas in which fluorine and fluoride compounds have a decisive impact. The individual volumes of Advances in Fluorine Science are thematic, addressing comprehensively both the science and applications on topics including the Environment, Green chemistry, Medicine, Health Life Sciences, New Technologies Materials Science, Energy and the Earth Sciences. 

Nowadays, the investigation of any important scientific topic needs a broad interdisciplinary approach, which creates a cross-fertilization of different skills and competence. The conception of the book Advanced Inorganic Fluorides Synthesis, Characterization and Applications was formulated in such a scope by bringing together specialists in inorganic chemistry, solid state chemistry, catalysis, material sciences and solid state physics. 

Maximum benefits to both deciduous and permanent teeth may result from daily fluoride supplements from infancy until approximately 13 years of age, at which time all permanent teeth except the third molars should have erupted. Because cariostatic benefits may tend to diminish gradually after fluorides are discontinued, periodic applications of topical fluorides may then be necessary. 

Topical concentrated fluoride solutions are useful in children with high caries activity because they may have both a caries-arresting property and one of caries prevention. The frequency of application varies with the caries activity of the child. For children with an average incidence of caries, it can be applied annually between the ages of 3 and 13. 

A number of studies have reported that topical fluoride application may reduce dental hypersensitivityJ ° These results have been found when concentrated dosage forms have been applied ranging from 8% stannous fluoride gels to 33.3% sodium fluoride paste. It has been shown that commercial dentifrices containing stannous fluoride may also decrease dental hypersensitivity. Also, a combination of stannous fluoride and potassium nitrate is marketed by one manufacturer to reduce sensitivity. Varnishes containing sodium fluoride have also been shown to reduce dental hypersensitivity. 

Zero DT, Raubertas RF, Pedersen AM, Fu J, Hayes AL, Featherstone JDB Studies of fluoride retention by oral soft tissues after the application of home-use topical fluorides. J Dent Res 1992 71 1546-1552. 

Winemakers have the important, yet pleasant task of frequently tasting the finished product. A winemaker developed widespread dental erosion attributed to the regular swilling of wine around the mouth (Ferguson et al. 1996). The acidic content of wine can erode the teeth. Topical fluoride applications or rinsing the mouth with alkaline solutions that do not interfere with the tasting procedure may be useful to protect the teeth. 

This article is concerned with two aspects of interatomic distances in crystals. The first problem is that of predicting interatomic distances to be expected in a given crystal structure as yet unknown. The second concerns the interpretation of observed distances in known structures. As they rely largely on empirical correlations, these two topics are closely interwoven. Most of the discussion will be devoted to materials such as oxides, nitrides and fluorides for which a large data base of structures exists, but in fact the treatment is of wider applicability. 

It will be apparent from the topics described in the sections above that fluorinated chromia has subtleties that are not completely understood and in some catalytic systems have so far been described incompletely. Some factors are clear however. The surface properties depend crucially on the extent of surface prefluorination. Although many laboratory studies have employed CFC or better HFC reagents, such surfaces are normally lightly fluorinated only, and in the case of CFCs will inevitably contain surface chloride species that complicate interpretation of the catalysis. For large-scale applications, anhydrous HF is the prefluorination (and fluorination) reagent of choice. The process is slow and, even at the surface level, is probably never complete. This is beneficial, since complete conversion to a chromium(in) fluoride layer, it is generally agreed, would result in a catalyst whose activity was very low or which was inactive. 

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